Vintage onions? I assume this means some sort of heirloom variety. I just love a caramelised and lightly toasty onion, an amazing fact about onion is it tastes great even when turned into charcoal! No charcoal here though, and all up a rich and tasty little dish. Each shell of onion a moment of bliss, and the bittercress a worthy addition to the texture and flavour. Not quite sure about the truffle-sprinkle on the plate… I scooped it up into the onion shells.